Gross Reservoir
Expansion Project


Gross Reservoir
Expansion Project


This short video summarizes Denver Water’s community commitments based on years of study and robust outreach to Gross Reservoir neighbors. Also, read more on our Community Responsiveness page and on !

Jeff Martin, Denver Water’s program manager on the Gross Reservoir Expansion Project sits for an interview about the project goals, core values and minimizing inconvenience to our neighbors.

Environmental Commitments

Provide $2 million towards aquatic habitat improvements on the Upper Colorado River.

Provide $1 million to the Upper Colorado River Wild and Scenic Management group to fund flow-related projects to protect the outstanding and remarkable values within segments of the Upper Colorado River.
Provide $6 million to Grand County to use towards environmental projects, and continue to participate in the “Learning By Doing” collaborative effort, which has already resulted in tangible positive environmental impacts on the West Slope.

Construct and maintain sediment pond on Berthoud Pass to keep the Fraser River bottom clean. Check out, “Good for drivers, bad for the Fraser River.”

Restore a portion of Fraser Flats in Grand County. Check out, “Keep it cool: Good for the Fraser River and its trout.”

Release water into Ranch Creek in response to high temperatures found through water temperature monitoring. Check out, “Searching for solutions to help trout keep their cool.”

Monitor stream temperatures and water quality in Gross Reservoir, South Boulder Creek and the Fraser River Basin.

Provide funding towards Colorado Parks and Wildlife’s cutthroat trout habitat projects to protect and restore native trout populations.

Through a cooperative process, replace culverts on Fraser River, Cabin Creek and St. Louis Creek with aquatic organism passage culverts that will enable free passage of fish and other aquatic organisms.

Provide flushing flows in the Williams Fork and Fraser River basins.

Provide more than 1,000 acre-feet of water in Grand County for environmental purposes.

Complete a stream restoration project on South Boulder Creek.

Create an environmental pool in Gross Reservoir that will be managed by the Cities of Boulder and Lafayette to provide flows into South Boulder Creek during periods of low or no flows.

Allow Grand County to store up to 2,500 acre-feet of water in Williams Fork Reservoir for environmental purposes.

Complete a stream restoration project on the Williams Fork River.

Begin stream bank monitoring on the North Fork of the South Platte River and South Boulder Creek to identify erosion and/or unstable banks, and make repairs, as needed.

Construct a fish ladder on Cabin Creek in Grand County.

Convey approximately 540 acres of land near the Moffat Tunnel to the U.S. Forest Service for permanent protection and management as part of the National Forest System.

Protect raptor species, fight invasive species, relocate rare plant species and responsibly remove trees and brush in the reservoir’s expanded footprint.

Continue to participate in the U.S. Fish and Wildlife Service’s Upper Colorado River Recovery Program and the Platte River Recovery Implementation Program, both designed to protect endangered species.

Online Office Hours

Out of concern for the safety of our employees and community, Denver Water has suspended in-person office hours and events indefinitely.

We do offer online one-on-one appointments with our project representatives who can answer your questions about the Gross Reservoir Expansion Project. We invite you to search for an available time and book an online meeting here.

We look forward to speaking with you!


Federal Lawsuit Dismissal Order

April 1, 2021 - Today’s decision is an important step. We will continue working earnestly through Boulder’s land-use process and look forward to beginning work on a project critical to water security for 1½ million people and to our many partners on the Front Range...

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Osprey Point Closure

Nov. 30, 2020 - Beginning the week of Nov. 30, Denver Water will be performing a safety project at the Osprey Point boat ramp at Gross Reservoir. This project will remove unstable rock at the boat ramp to ensure a safe environment for the public and Denver Water...

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Going electrofishing on the Fraser Flats

TAP - Nov. 20, 2020 - "The data from the fish surveys are shared with Learning By Doing, a unique partnership between East and West Slope organizations in Colorado that focuses on maintaining the aquatic environment in Grand County and improving conditions when...

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